The present invention relates generally to a dispensing apparatus, and more particularly, to an apparatus to facilitate attachment of an operator-controlled dispensing gun to a pressurized container for fluent products.
In recent years, significant advances have been made in packaging fluent products used for a variety of purposes, particularly those in the field of construction and repair. For example, "aerosol" or other pressurized containers for adhesives, caulking materials, insulating foams, and similar products have become increasingly common.
The convenience and other advantages of aerosol or other pressurized containers can be significant in many applications. Thus, while manually operated caulking guns are well known and generally satisfactory, a certain amount of skill is required to achieve a uniform dispensing rate. Caulking contained in tubes and dispensed by ratchet-operated trigger mechanisms inherently require repositioning the trigger after a certain volume has been dispensed, leading to uneven and irregular dispensing.
Coordinating the movement rates of a trigger or other device with the rate of moving the container during product application often requires more concentration and coordination than an occasional user, such as a hobbyist, is able to muster, with the result that the visual or functional effect of the product being dispensed is compromised. If the product being dispensed is one whose appearance will be highly visible, uniformity of dispensing may be an important consideration. Where structural strength or integrity is important, such as with adhesives or sealants, uniformity and/or sufficiency of dispensing can be critical.
Very recently, improved dispensing guns have been developed whereby the bead size of a fluent product such as a caulk, adhesive, or insulating foam material (either "expanding" or "non-expanding") can be carefully controlled and flow can be shut off at the tip of the gun rather than inside the valve, thereby minimizing so-called "drooling" or flow after the valve is shut off. Such guns, including those referred to in my pending patent application Ser. No. 08/264,641 filed Jun. 23, 1994 have proven successful in achieving a degree of control that is not achievable with ordinary aerosol or similar pressurized containers.
However, guns of this and other types which are adapted to be used with a single, moderate size can, i.e., 12 to 24 ounces, for example, although not expensive in some respects, are most economically utilized when the user intends to dispense several containers of product in connection with a single project. Guns of the above-referenced type that possess a handle and a trigger separate from one which may merely be positioned atop the valve of an aerosol unit, require attachment systems that have cooperating counterparts on the aerosol cans.
Thus, where it is known that containers of dispensable product are to be used with a special-purpose gun, then the container and the gun may have preformed mating parts to facilitate proper attachment and sealing of the gun and the container. While this is convenient, safe, and effective in use, it does have the drawbacks of requiring a particular container to be dedicated to use with the gun. This in turn can create undesirable problems of inventory control, particularly with resellers who do not wish to stock redundant inventory, i.e., inventory wherein two essentially identical products must be treated as different from each other. Manufacturers do not prefer to make two different style packages of substantially identical product, particularly where the intended application for both styles of containers is the same.
Accordingly, it would be desirable if a simple and inexpensive adapter system could be made for existing pressurized containers whereby the choice could be made by the packager, the retailer or the customer to provide a dispensing valve in association with the can itself or to render the can useful with a special purpose gun, and do so in a highly effective, very inexpensive manner. It would also be advantageous if such an adapter system could be made to incorporate a low risk form of operation, i.e., one which reduces the chance of misalignment, accidental leakage, or unintended discharge of the container contents during gun attachment.
It would also be desirable if an attachment system of a simple kind could be made for dispensing containers, particularly where such system could be made at low cost. An ideal attachment system would be one wherein the attaching ring or the like could be made in a simple manner for compatibility with various existing valve systems and/or gun attachment systems such as bayonet locks, wedge type units or threaded style valve actuators.
Likewise, it would be further advantageous if an adapter system could be provided wherein the user or the retailer could either add a simple low cost component to existing cans or, in the alternative, could remove such an adapter if it were pre-fitted to the container but not desired for use, all without risk or the involvement of measurable technical or mechanical skill.
In view of the failure of the prior art to provide the highly effective, low cost adapter or attachment systems permitting dispensing guns to be used with low cost containers of fluent materials, it is an object of the invention to provide an improved system for this purpose.
Another object of the invention is to provide a twist lock system for dispensing containers wherein the system includes a specially designed locking ring that is readily affixable to the valve assembly of a low cost aerosol container, using a dual plane or other arrangement of cooperating locking lugs on an associated gun.
Still another object of the invention is to provide a twist lock type adapter for converting an aerosol can with a manually actuable valve to a can that can be securely locked to a separate, trigger-operated dispensing gun.
A further object of the invention is to provide a dispensing gun having a combination twist lock and valve actuating system including one or more pairs of locking lugs positioned in an offset, dual plane arrangement so as to avoid accidental actuation of the can dispensing valve.
Yet another object of the invention is to provide an attachment and valve actuating system wherein a ring style adapter can be used that is compatible with various inclined plane or ramp-type actuators, coarse thread mechanisms or other similar simple attachment systems.
A still further object of the invention is to develop a dispensing gun having a safety-type twist lock and a valve capturing an actuating system forming a part of its product inlet, whereby the container valve cannot be actuated unless the container and gun are properly positioned relative to each other. Yet another object of the invention is to provide a locking ring adapter for an aerosol can which ring may be readily detachable by the user but that resists accidental release from the can when in use on the product.
A further object of the invention is to provide an improved combination twist lock and gun positioning assembly including a dispensing gun with a pair of locking lugs spaced both circumferentially and axially apart or in a dual plane arrangement to insure positive positioning during the engaging/positioning and locking operations.
Another object of the invention is to provide a gun positioner of the type just described wherein the components are made of low cost material, such as a metal locking ring and a plastic locking lug assembly.
A still further object of the invention is to provide an adapter or attachment system which is useful with a variety of valves, including so-called Clayton valves, VCA valves, or other styles of valves including spring loaded valves, tilt action valves or the like.
The foregoing and other objects and advantages of the invention are achieved in practice by providing a twist lock system for a dispensing container which includes a locking ring for a pressurized container, a dispensing gun having a combination twist lock and valve actuating system including two pairs of radially and circumferentially spaced locking lugs cooperating with slots and the locking ring, an axially movable valve stem positioned in a body secured to the container end and a valve capturing and actuating surface formed on the dispenser gun, with the components constructed and arranged so that the valve cannot be actuated unless the container and gun are properly positioned.
The exact manner in which the foregoing and other objects and advantages of the invention are achieved in practice will become more clearly apparent when reference is made to the accompanying detailed description of the preferred embodiment of the invention set forth by way of example and shown in the accompanying drawings in which like reference numbers indicate corresponding parts throughout.